How much sats should a patient with COPD sit at?

Specialties Geriatric

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Hi All,

I have a question in relation to COPD in which I've struggled to find the answer too. I think I know the answer to it but just wanted clarify.

Today at work I had a patient with COPD. I'm aware with COPD to not put the 02 up higher than 2 L.

When I checked the sats on 1 L they where around 78-81%. With the patient asymptomstic. I put it up to 2 L just to help that bit more. We are aiming 88% above.

My in charge said that when the patient was sitting at 95% they where to much so to reduce the 02.

Is that because the 02 on and being 95% it would've increased meaning to much CO2 in the blood going around ?

I know this is probably a silly question and I know why we don't have to many litres on but not sure why she said 95% was to much for this patient.

Did she mean whilst the oxygen was on ?

Thanks heaps!!

Specializes in Gerontology, Med surg, Home Health.

It's hard to tell what she meant. Personally, I think you should go by your assessment of the patient and not

rely solely on the number on the pulse ox. The hard and fast rule of no more than 2 liters per minute on

a patient with COPD is not so hard and fast any more. It takes time for the CO2 to build up. If the patient is

satting at 78% on 2 liters, of course it would be wise to increase the liter flow until their sats go back up to the desired range. Not everyone needs to have their sats in the mid 90s.

Thank you so much for your feedback. As I said my assessments showed that the patient was also asymptomstic however I felt the need to increase the sats level before they became symptomatic till they reached a stable range criteria that we have for this patient.

I just wasn't 100% sure what my im charge could of meant by this.

You did just teach me something though so again thank you :)

86-92%

I haven't worked with adults in a few years, but in nursing school I think we learned that too much O2 can decrease the respiratory drive in COPD patients. The respiratory drive of normal adults is based on CO2 build up, but in COPD patients (who chronically retain CO2), the respiratory drive is based on O2 deprivation (hypoxia). So the concern with giving too much supplemental O2 is that you could depress the respiratory drive; I've never actually seen this in practice, but I'm guessing the major concern would be during sleep when the patient isn't aware that they're forgetting to breath.

Here's a wikipedia article on the topic (I know, not super-scientific): Hypoxic drive - Wikipedia

If it were me, in that case I'd ask for an order (or a unit protocol) to establish acceptable O2 parameters for patients like this. Patients with severe chronic lung disease can develop compensatory mechanisms that allow them to live at relatively low O2 sat levels (i.e. mid-to-low 80s).

1) Although you must address the numbers, always treat the patient first, the numbers second. Just a philosophical point. :D

2) The concern is indeed depressing the respiratory drive, which in COPDers increases (patient wants to breathe) when oxygen levels are low rather than when CO2 levels are high ('cuz this is normal for those with COPD). But you also want to keep in mind the fact that oxygen is a "drug" of sorts, with toxic effects at too high a dose; the patient shouldn't be given more than he can actually utilize, as extra Os will just turn into corrosive free radicals.

3) Chronic heart and lung diseases often create a chronic state of polycythemia; excess red blood cells maximize the body's oxygenation potential--remember, O2 saturation is a percentage. More cells=more available space for oxygen molecules to hitch a ride to hungry tissues. Normally, having lots of oxygen molecules in circulation is a good thing, but if the lungs are too fibrotic, hyper-inflated, or plugged up with mucus, all those extra Os can't get through and so they just turn into cellular poison. Which is another reason too many liters is bad. So, the answer to your question is--

It depends on the patient. (Sorry, but is does.) But, in general, 80-90% is a good range. The lower the peripheral saturation (pulse ox) gets, though, the faster the actual arterial oxygen saturation level drops (which means your patient is speeding toward dangerous hypoxemia--meaning cell damage--faster and faster with each percentage point he drops below around 88%). Therefore: Never withhold oxygen in a crisis, but always handle with care, especially in COPD.

Hope that helps!

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